Pneumatic spring device.



UNITED STATES PATENT GFFICE.

IRVING COWLES AND ERNEST H. HACDOWELL. F SOUTH HAVEN. MICHIGAN.

PNEUMATIC SPRING DEVICE.

pccllcatlon o! Letters Patent.

lutcnted Sept. l2, 19| l.

Application led April t3. 1908. Serial llo. 311,533.

To all whom it may concern:

llc it known that we. I avian Cownizs and lllixrts'r ll..\l.\i'l)owni.i., citizens of the vl'iiitcd States. residingr at Southllaven. iii 5 the county of Van llureii. State of Michigran. haveinvented certain new and useful lniproveineuts in lncuuiatic SpringDevices. of which the following is a spccitication.

This invention relates to improvements in spring or cushion devices.

ln vehicles. particularly iuotor vehicles, it isvery desirable to have aspring conn struction which is ca nible of sustaining vei'v heavy loadsand at tlie same time one which ia very elastic.

Our spring device is especially designed for use on motor vehicles,although it is desirable for use in numerous other` relations. such `ascarriages, wagons, cars, and the like.

The objects of Athis invention are; First', to provide an improvedspi-ing device which is veiy elast-ic and at the saine time capable ofcarrying "ery heavy loads. Second. to provide an improved spring.rdevice iii which the iecoil or return iseasy and gradual. Third, toprovide an ini iroved spring device which niay be quickly adjusted tothe load it is to carry. Fourth. to provide an improved springr device.embodyinY the above advantages which is very sinipe and economical instructure.

Further objects. and objects relating! to structural details willdefinitely appear from the detailed description to follow.

' We accom ilish the objects of our iiivelition bv the (evices andineaiis described in the following specification.

The invention is clearly defined and pointed out in the claims.

A structure embodying the features of our invention' isv clearlyillustrated in the accompanying drawing'forming` a part of this 46specification, in which- Figure 1 is a detail view of a structurecuibodving the features of our invention, artia ly in section, on line1-1 of Fig. 2. i is ii detail vertical section on line 2-2 6o of ig. 1.Fig. 3 is a liorzontalsection on line 3-3 of Piz. 2. Fig. 4 is anenlarged detail section showing the arrangement ol the bypliis E" forthe valve E'. Fig. 5 is an enlarged detail section on a line corre- 55spending to line 5- 5 of Fig. 1. In the drawing the sectional views aretaken lookingr in the direction of the little arrows at thc endsof thesection lilies. and .similar letters of reference rel'ci' to lsiiuilarparts throughout. the .several views.

Referringr to the drawing. represents the axle of a vehicle. and A' nspring. a seniiclliptical spring beine illustrated.

A" represets a vehicle body.

The cylinder B is secured to the axle by the clip C. The cylinder isconnected to this clip by the pivot; bolt. c', which is arrangedtransversely of the axle. through a downwardly projecting ear on t-liecylinder.

'itliin the cylinder is a plunger B' which is connected by the plungerrod lV to the vehicle body. The plun 'er rod l ia piv-.vitally-connected byva bo to". thus forming a universal jointconnection for the plunger rod to the vehicle body. The coupling membera, is preferably rovided with' a series of holes a" for the lt a so thatconsiderable latitude of adjustmentis provided.

The tank D is secured to the under side of the vehicle body by suitablehangers. This tank is connected to the lower end of the cylinder B bymeans of the pipe E and the flexible pipe F. .ln practice we irovide apair of the cylinders for each axle. Tlicv arc all preferably connectedto the tank as isiiidicatcd in Fig. 1. there being a T- shaped couplingrF at each end of the tank to which the flexible tubes F'l are connected.

In the pi ie Eris a check valve E' which allows the l uid to pass freelyfrom the cylinder but checks its return. This valve is provided with abypass E". (See Figs. 1 and 4.) This bypass allows the lluid to returnslowly to the cylinder after being forced therefrom. A needle valve, as'e, is provided for this bypass.

T he tank D is preferably partially filled with oil or other li uid, theliquid also tilliiig the cylinder be ow the piston and the pipeconnections for lthe piston to -the tank I). The tank D is adapted vtocontain air under pressure. and Serves as n compression `cha'iiber forthe cylinder, and we preferablv provide the same with aieressure gageD'" and a liquid rage D". e Fig. 1.)

'lhe tank l is preferably provided with a fillingr pipe 1) whichproiects upwardly through the loor of the vciiclc body, the body nothere illustrated. A suitable pneumatic valve, as Il, is provided for thepi )e D'.

In the inner end of the cylinder Bis an tlO inwardly o ening air inletvalve l. This valve is a e teck valve. and is held normally in its seatby a suitable .-pring. When tbe plunger is forced downward the suctioncaused thereby o )ens the valve and allows the air to llow t trough thesaine. In the cylinder. toward its inner end, is an air exhaust port L',which allows the escape of tbe air on tl'e return or n )ward movementot' the plunger. valve I is provided for regulating the size ol' theesca pe port, thcreby controlling the return of the plunger.

'lo protect the valve l and the upper end of the cylinder ll from dirt,we provide a cap (ir which is perforated to receive the plunger and issecured to the cylinder by suitable set screws.

In operation, the tank I) is tilled with air umler pressure. sullieientpreferably to raise the body of the vehicle slightly above its normalposition when not carrying a load. When the vehicle is loaded, the loadis in etlect supported on an air cushion. In easey of a blow beingdelivered to the axle, as by the engagement of the wheel carried therebvwith an obstruction in the road, the plunger ll is given a relativelydownward movement in the cylinder in opposition to the pressure of the.lluid contained therein. The apncitv of the cylinder is small, relativeto that of tbe chamber I), and eonsefpiently the pressure in the systemis only slightly increased by the movements of the .plungers to theirlmverznost positions. n this downward movmnent' of the cylinder, airtlows into the cylinder behind tbc plunger through the valve l1. 0n thereturn ot' the plunger the nir escapes through the exhaust i', whichallows the air to escape slowly, thereby prevontingrthe quick return ot'the plunger. 'l'he inner part 'of the c vlindcr above the exhaust 'formsan air cushion, so that the vreturn movement is gradually chisel-zeil,thereby preventing tbe disagreeable throw incident to springs ol'ordinary construction,the shock ol' the return being entirely ahsorlmdin the spring device.

. We preferably use our spring gear in eonjunction with metal springs ofthe usual or :tn v desired construction which serve to hohl tln.l bod)lagainst .swaying movement. Other means might, however bc employed. liyconnecting the four ey inders provided for each \'telitiele\\'itli tieonuuon air elnunluer. the vehicle body is evenly supported throughout.

Uur improved spring device carries tite vehicle body very evenly atul atthe same linie'bas all ol' tbe advantages ol' very resilient springe'l'he return or recoil incident. to .-uch springs is overcome, so thatwhere springs are. used in connection with oar device the danger ol'breaking is obvintcd and tbe'objectionable throw' ell'ect. eliminated.

ln charging the device, the vents in the cylinders closed by the. .screwplugs. are opened to allow the escape ot' the air from the cylindersbelow thc plungers.

We have illustrated and described our imm'ovetuents in detail in theloria prcferred by us on account of structural econonly and conveniencein attaching to the vehicle. 'e are, however. aware that it is capableof very great. stt'netural variation without. departing from ourinvention: and, while we have, as stated, |a'.rticnlarl v designedthesntne for use on motor vehicles, such as automobiles, it is desirablel'or use in a great many ol her t'elat ions.

llaving thus described our invention, what'. we claim as new and desire-to secure by Letters Patent, is

l. I'n a cushioning device. a reservoir containing a lliquid and agaseous lluid under n'essure, a sustaining device adapted to beinterposed between two relatively movable bodies to support one abovethe other and including a cylinder eonnnunicating with said reservoir.and containing a reciprocat'ory piston operating in one direction solelyaeainst a (-.onipressiblc 'lluid and in the other dn'eetion solelyagainst the liquid sutpplied .from sind reservoir. said liqiconstituting0 a vehicle for the transmission ol' the pressure ol' saidgaseous lluid in said reservoir to said piston \\'hereby the liquid willsastain the latter. and means interposed in said communieation betweensaid cylinder and reservoir for autolmitically var viner the llow ol'liquid'to and from thel said cylinder respectively.

2. ln a cushioning device, n reservoir containing a liquid and a gaseouslluid under pressure, n sustaining device adapted to be interposedbetween two relatively movable bodies to support one above tbe other andincluding a cylinder ctunmunieatine' with said reservoir und containinga rcciprm'atory piston qa-rating in one direction .solelyr against. ncont n'essible lluid und in the other direction sole y against theliquid supplied l'rom said reservoir. said liquid constituting a vehiclefor the traits-mission ol' tlee pressure ol" saidv gaseous' lluid insaid reservoir to said piston wherebyI the liqui'! will sus-- tain tbclattcinn check valve interposed in .said comumnieation to prevent thetlow ol liquid l'rout said reservoir to .said evlindcr, und n bvpassl'or said check valve,

' il. In a cushioning dcviee.'a reservoir containing a liquid and a:faseons tlnid under pressure. a sustaining device adapted to be`interposed between two relatively movable. lunlics tu .support one nlmvcthe other ttul including a cylinder eonunnnicatini! with said 'reservoirand containing a recita-'aah tory piston operating in one directionsolely against a eunpre\--ilde lluid ned in the other direction I-olclyagainst tbc liquid supplied l'riun said resc|'\oir,-.-ail liqni-lcoietituting a vehicle for the transmission of the pressure of saidgaseous fluid in said reservoir to said piston whereby the litnidwillfsustuin the lutter, u chock valve interposed in saidcouiiuunicalion to prevent the flow of liquid from said reservoir tosaid cylinder, a b v-pass for said check valve, and a control valve forsaid by-p-.iss.

4. ln a cushioning device, a reservoir containing: a liquid and agaseous fluid under iressjure, a sustainingI device adapted to beinterposed between two relatively movable bodies to support one abovethe other and including a cylinder communicating with said reservoir-umlcontaining a reci-proce tory piston operating in one direction solelyagainst a com iressible fluid and in the other direction sole y againstthe lii uid supplied from said reservoir, said liqiii constituting avehicle for the transmission of the pressure ol' said gaseous lfluid insaid reservoir to said piston whereby the liquid will sustain thelatter, means interposed in said communication lietweeii said cylinderand reservoir for aiitolnatically var ing the flow of liquid to and fromthe sait cylinder respectively, and means for trappingthe coinprcssiblefluid against which' said piston acts thereby providing a retardingmedium for the movement. ofthe piston in the first named direction.

5. In a cushioning device, a reservoir containing a liquid and a gaseousfluid under pressure, a sustiiiniupr device adapted to be interposedbetween two relatively movable bodies to support, one above the otherand including a cylinder communicating with said reservoir andcontiiinin f a reciprocatory piston operating in one t irection solelyagainst u com iressilile fluid and in the other direction sole y againstthe lit uid supplied from said reservoir, said liquii constituting avehicle for the transmission ofthe pressure of said gaseous fluid insaid reservoir to said piston wlierebv the liquid will sustain thelatter, a ehcclc valve interposed in said communication to prevent theflow of lii uid l'roiii said reservoir to said c lindcr, a iypiiss forsaid cl'ieek valve, an means for trapping the tuimpresaiblo fluid aaiiist which said pistou acts thereby provi ing a retardiug medium forthe movement of the piston iu the tiret iuiined direction.

ti. ln a cushioning' device, a. reservoir containing a liquid und agaseous fluid under ii'esiuire. u sustaining device adapted to beinterposed between two relatively movable bodies to support one abovetlie other und including u cylinder couuniuiicutiug with said reservoirand containing a reciprocatory piston operation in ouc direct ion solelyagainst a coiuprcssililc fluid aiul in the other direction solelyagainst the liquid supplied from said resi 'wou'. said liquidconstituting: a vcliicle l'or the transmission of the pressure ot' saidgaseous fluid in said reservoir to said piston wliereb the liquid willsustiiin the latter, a chec valve interposed in said communication toprevent the how of liquid from said reservoir to said cylinder, aby-pass for said check valve, a control valve for said by-pass, andmeans for trapping the conipressible fluid against which said pistonacts thereby providing a retard-' ing medium for the movement of thepiston in the first named direction.

7. In a cushioning device, a reservoir con taining a liquid and agaseous fluid under iressurc, a sustaining device adapted to lieinterposed between two relatively movable bodies to support one abovethe other and including al c 'liuder communicating with said reservoirand containing a reciprocatory piston operating in one direction solelyagainsta conipressible fluid and in the other direction solely against.the liquid supplied from said reservoir, said liquid constituting a.

vehicle for the transmission of the pressure of said gaseous fluid insaid reservoir to said iistou whereby the liqiiidwill sustain the utter,and nieans for trapping,r the coiiipres-A sible fluid against which saidpiston acts thereby providing a retarding medium for the movement. ofthe piston in .the first naiued direction.

8. In a cushioning device, a reservoir con taining.:` a liquid and agaseous fluid under iressure, a sustaining device adiipted to beinterposed between two relatively movable bodies to support one abovethe other and i' cludinga cylinder communicating willi saiu reservoirand containing a rcriproeatcry piston operating' i'i one directionsolely against u com ircssible fluid and in the utlicidireetion sole yagainst the li uid supplied from said reservoir, said liquiiconstituting a vehicle for the transmission' of the pres. sure of saidgaseous fluid in said reservoir to said piston wlierebv the liquid willsustain the latter. said cy iiider provided with an inlet )ort for thecouipi'essblc fluid against which the piston actsdind a check valve forcontrollini,t said poi't thereby trappini.,r said compressi le fluid,and providingr a retardini; niediuin for the movement ot' the piston inthe first named direction.

t). fn a cushioning' device, a reservoir containing u liquid and agaseous fluid maler pressure. u sustuiniuq device adapted to beinterposed between two relatively movable bodies to support. one abovethe other and including a cylinder communicating with said reservoir andi-.outaininga i'ia'iproeatory pistou operating iu one direction solelyagainst a eoiupi'essible fluid and Iiu the otlici direction solelyagainst the' lii uid mipplied l'ioiii said reservoir. said liqjiitlconstituting :i vehicle loi' tlic transmission of the pressure ol' saidgaseous fluid in said reservoir to said piston whereby the liquid iiillsustain direction, and snit the latter. and ineaiis foii'trappiugthecouipressible tluid against which said piston acts thereby providinga i'ctarding inedinni for the num-nient of the piston in the iirst-iianied direction, said cylinder provided with means whereby the volumeof conipressihle tluid trapped to constitute the retarding nicdiuni iscontrolled.

10. ln a cusliioiiinfr device, urcservoir containing a liquid and agaseous fluid under ircssure, u sustaining device adapted to beinterposed between two relatively movable bodies to support one abovethe other and including a cylinder communicating with said reservoir undcontaining a reciprocator'r piston operating in one direction solely'against a conqircssiiile tluid und in the other direction solely againstthe li uid supplied from said reservoir, said liquid constituting avehicle for, the transmission of the pressure of said gaseous [luid insaid reservoir to said piston whereby4 the liquid will sustain thelatter, means for trapping the compressible tluid against; which saidpiston acts thereby providing` a rvtarding medium for the movement ofthe piston in the first iiuined direction, and said c vlin'der providedwith means controlled by thc movement of vthe piston for regulating thevolume of comprensible tluid trapped to constitute the retardini:medium,

11. In a cushioning device, a reservoir containing a liquid and a eseoustluidnnder pressure, a sustaining i evice adapted to be inter ioscdbetween two' relatively :movable bodies to support bite above the otherund including a cylinder communicating .with said reservoir andcontaining a recil'irocatory piston operating in one direction solelyagainst a comprensible tluid 'and' in the other direction solely againstthey liquid supplied from 4said reservoir, said' lit uid. constitutingapvehcle'tw 'the transe mission of the pressure o said gaseous fluid. insaid reservoir to said piston ,whereby the liquid will sustain thelatter, said cylinder provided with an inlet, port lfor the coin- 4pressible tluid against which the iston. acts, a check valve forcontrolling sai ort thereby trapping ,said compressible uid andproviding a retarding medium for the movement of the piston 'in thelfirst named cylinder provided with 'niea'n's controlled by the movement-bf the piston, for rpiulating the volume of oompres'sible viluijtrappcd to constitute the rc tardin mcdittm. `..`12. n iefcushioningdevice,.a reservoir' l ciuitainingu liquid and a gaseous tluid underpressure, a sustaining device adapted to "berinterposcd between tworelatively mo'vable bodies to support one above the other, and includinga .cylinder communicating with said reservoir 'and containing a re'-cylinder provided with an exhaust port conf' trollcd by the movement ofthe piston tor regulating the volume of compres-sible tluid trapped toconstitute thc rctarding ineiliuin.

13.1n a cushioning device, a reservoir containing a 'liquid and agaseous tluid under pressure, a sustaining device adapted to beinterposed between two relatively movable bodies to support one abovethe other and including a cylinder communicating with said reservoir andcontaining a reciprocatory piston operating; in one direction .fiolely/against a coinpressiblo tluid and in the other direction solely againstthe liquid supplied from said reservoir, said liquid constituting avehicle Afor the transmission of the pressure of said gaseous tluid insaid reservoir to said piston whereby the liquid will sustain thelatter, a cheek valve interosed in said communication to prevent the owof liquid from said reservoir to said c lilider, n by-pass. for saidcheek valve, n clieck-valve controlled inlet poi-t for the admission andtruiiping of compres-sible tluid to provide a retardiug medium for themovement of the pistou in the first named direction, and said cylinderprovided with 4means controlled by the movement. of the piston forregulating the volume of coinpressible tluid trapped to constitute thereder pressure, a sustaining device adapted t0. .11(

be interposed between two relatively movable bodies to support one abovethe other and including ay cylinder communicating with said reservoirand containing a reciprocatory piston .operating in one direction solelyagainst a coinprcssihle tluid and in the other direction solely against.the liquid supplied from said reserviiir, said liquid constituting avehicle for the transmission of the pressure of said gaseous tluid insaid reservoir to said piston whereby the liquid will sustain thelatter, a check valve interposed in said communication to prevent thetlo'vv of liquid from said reservoir to said cyliiidei', a by-pass forsaid check valve, a

.control valve for said by-pass, a check-vulve

